Tri-substituted triazines

ABSTRACT

Tri-substituted s-triazine di and triimino substituted alkyl and aryl mono and dicarboxylic acids and salts thereof useful as complement inhibitors.

This application is a divisional of applicants' co-pending application,Ser. No. 811,101, filed June 29, 1977, now U.S. Pat. No. 4,132,850.

DESCRIPTION OF THE INVENTION

This invention is concerned with compounds of the formula: ##STR1##wherein R₁ is selected from the group consisting of hydrogen andcarboxymethyl; R₂ is selected from the group consisting of carboxymethyland ##STR2## wherein R₄ is selected from the group consisting ofchlorine and ##STR3## wherein R₁ and R₂ are as previously defined; andthe pharmaceutically acceptable salts thereof.

A preferred embodiment of the instant invention consists of thosecompounds wherein R₁ is hydrogen; R₂ is selected from the groupconsisting of ##STR4## wherein R₄ is selected from the group consistingof alkali metal; and R₃ is selected from the group consisting of##STR5## wherein R₁ and R₂ are as previously defined. Some of thecompounds of the present invention may be prepared by reacting theappropriate alkyl imino acid salt in water with cyanuric chloride (inacetone) in the presence of sodium bicarbonate. The mixture is stirred 2hours, refluxed 16 hours, acidified and allowed to crystallize. Theproduct is recrystallized from water as the hexa acid.

Some of the compounds of the present invention may also be prepared byreacting the appropriate aryl amino acid in aqueous solution withcyanuric chloride (in acetone) in the presence of alkali metalbicarbonate. The mixture is stirred 31/2 hours at 40°-45° C. then isfiltered and concentrated. The product is isolated from water withethanol as the tetra alkali metal salt. When the tetra alkali metal saltis refluxed for 15 hours with the aryl amino acid in aqueous solution inthe presence of alkali metal bicarbonate the product is isolated fromwater with ethanol as the hexa alkali metal salt.

The term "complement" refers to a complex group of proteins in bodyfluids that, working together with antibodies or other factors, play animportant role as mediators of immune allergic, immunochemical and/orimmunopathological reactions. The reactions in which complementparticipates take place in blood serum or in other body fluids, andhence are considered to be humoral reactions.

With regard to human blood, there are at present more than 11 proteinsin the complement system. These complement proteins are designated bythe letter C and by number: C1, C2, C3 and so on up to C9. Thecomplement protein C1 is actually an assembly of subunits designatedC1q, C1r and C1s. The numbers assigned to the complement proteinsreflect the sequence in which they become active, with the exception ofcomplement protein C4, which reacts after C1 and before C2. Thenumerical assignments for the proteins in the complement system weremade before the reaction sequence was fully understood. A more detaileddiscussion of the complement system and its role in body processes canbe found in, for example, Bull. World Health Org., 39, 935-938 (1968);Ann. Rev. Medicine 19, 1-24 (1968); The John Hopkins Med. J., 128, 57-74(1971); Harvey Lectures, 66, 75-104 (1972); The New England Journal ofMedicine, 287, 452-454; 489-495; 545-549; 592-596; 642-646 (1972);Scientific American, 229, (No. 5), 54-66 (1973); Federation Proceedings,32, 134-137 (1973); Medical World News, October 11, 1974, pp. 53-58;64-66; J. Allergy Clin. Immunol., 53, 298-302 (1974); Cold Spring HarborConf. Cell Proliferation 2/Proteases Biol. Control/229-241 (1975);Annals of Internal Medicine, 84, 580-593 (1976); "Complement: Mechanismsand Functions", Prentice-Hall, Englewood Cliffs, N. J. (1976).

The complement system can be considered to consist of three sub-systems:(1) a recognition unit (C1q) which enables it to combine with antibodymolecules that have detected a foreign invader; (2) an activation unit(C1r, C1s, C2, C4, C3) which prepares a site on the neighboringmembrane; and (3) and attack unit (C5, C6, C7, C8 and C9) which createsa "hole" in the membrane. The membrane attack unit is non-specific; itdestroys invaders only because it is generated in their neighborhood. Inorder to minimize damage to the host's own cells, its activity must belimited in time. This limitation is accomplished partly by thespontaneous decay of activated complement and partly by interference byinhibitors and destructive enzymes. The control of complement, however,is not perfect, and there are times when damage is done to the host'scells. Immunity is therefore a double-edged sword.

Activation of the complement system also accelerates blood clotting.This action comes about by way of the complement-mediated release of aclotting factor from platelets. The biologically active complementfragments and complexes can become involved in reactions that damage thehost's cells, and these pathogenic reactions can result in thedevelopment of immune-complex diseases. For example, in some forms ofnephritis, complement damages the basal membrane of the kidney,resulting in the escape of protein from the blood into the urine. Thedisease disseminated lupus erythematosus belongs in this category; itssymptoms include nephritis, visceral lesions and skin eruptions. Thetreatment of diphtheria or tetanus with the injection of large amountsof antitoxin sometimes results in serum sickness, an immune-complexdisease. Rheumatoid arthritis also involves immune complexes. Likedisseminated lupus erythematosus, it is an autoimmune disease in whichthe disease symptoms are caused by pathological effects of the immunesystem in the host's tissues. In summary, the complement system has beenshown to be involved with inflammation, coagulation, fibrinolysis,antibody-antigen reactions and other metabolic processes.

In the presence of antibody-antigen complexes the complement proteinsare involved in a series of reactions which may lead to irreversiblemembrane damage if they occur in the vicinity of biological membranes.Thus, while complement constitutes a part of the body's defensemechanism against infection it also results in inflammation and tissuedamage in the immunopathological process. The nature of certain of thecomplement proteins, suggestions regarding the mode of complementbinding to biological membranes and the manner in which complementeffects membrane damage are discussed in Annual Review in Biochemistry,38, 389 (1969).

A variety of substances have been disclosed as inhibiting the complementsystem, i.e., as complement inhibitors. For example, the compounds3,3'-ureylenebis-[6-(2-amino-8-hydroxy-6-sulfo-1-naphthylazo)]benzenesulfonicacid, tetrasodium salt (chlorazol fast pink), heparin and a sulphateddextran have been reported to have an anticomplementary effect, BritishJournal of Experimental Pathology, 33, 327-339 (1952). The compound8-(3-benzamido-4-methylbenzamido)naphthalene-1,-3,5-trisulfonic acid(Suramin) is described as a competitive inhibitor of the complementsystem, Clin. Exp. Immunol., 10, 127-138 (1972). German Patent No.2,254,893 or South African Patent No. 727,923 discloses certain1-(diphenylmethyl)-4-(3-phenylallyl)piperazines useful as complementinhibitors. Other chemical compounds having complement inhibitingactivity are disclosed in, for example, Journal of Medicinal Chemistry,12, 415-419; 902-905; 1049-1052; 1053-1056 (1969); Canadian Journal ofBiochemistry, 47, 547-552 (1969); The Journal of Immunology, 93, 629-640(1964); The Journal of Immunology, 104, 279-288 (1970); The Journal ofImmunology, 106, 241-245 (1971); and The Journal of Immunology, 111,1061-1066 (1973).

It has been reported that the known complement inhibitorsepsilon-aminocaproic acid, Suramin and tranexamic acid all have beenused with success in the treatment of hereditary angioneurotic edema, adisease state resulting from an inherited deficiency or lack of functionof the serum inhibitor of the activated first component of complement(C1 inhibitor), The New England Journal of Medicine, 286, 808-812(1972). It has also been reported that the drug,pentosan-poly-sulfoester, has an anticomplementary activity on humanserum both in vitro and in vivo, as judged by the reduction in totalhemolytic complement activity; Pathologie Biologie, 25, 33-36 (1977).

The compounds of the present invention may be administered internally,e.g., orally, intra-articularly or parenterally, e.g., intra-articular,to a warm-blooded animal to inhibit complement in the body fluid of theanimal, such inhibition being useful in the amelioration or preventionof those reactions dependent upon the function of complement, such asinflammatory process and cell membrane damage induced byantigen-antibody complexes. A range of doses may be employed dependingon the mode of administration, the condition being treated and theparticular compound being used. For example, for intravenous orsubcutaneous use from about 5 to about 50 mg/kg/day, or every six hoursfor more rapidly excreted salts, may be used. For intra-articular usefor large joints such as the knee, from about 2 to about 20 mg/joint perweek may be used, with proportionally smaller doses for smaller joints.The dosage range is to be adjusted to provide optimum therapeuticresponse in the warm-blooded animal being treated. In general, theamount of compound administered can vary over a wide range to providefrom about 5 mg/kg to about 100 mg/kg of body weight of animal per day.The usual daily dosage for a 70 kg subject may vary from about 350 mg toabout 3.5 g. Unit doses of the acid or salt can contain from about 0.5mg to about 500 mg.

While in general the sodium salts of the acids of the invention aresuitable for parenteral use, other salts may also be prepared, such asthose of primary amines, e.g., ethylamine; secondary amines, e.g.,diethylamine or diethanol amine; tertiary amines, e.g., pyridine ortriethylamine or 2-dimethylaminomethyl-dibenzofuran; aliphatic diamines,e.g., decamethylenediamine; and aromatic diamines, can be prepared. Someof these are soluble in water, others are soluble in saline solution,and still others are insoluble and can be used for purposes of preparingsuspensions for injection. Furthermore as well as the sodium salt, thoseof the alkali metals, such as potassium and lithium; of ammonia; and ofthe alkaline earth metals, such as calcium or magnesium, may beemployed. It will be apparent, therefore, that these salts embrace, ingeneral derivatives of salt-forming cations.

In therapeutic use, the compounds of this invention may be administeredin the form of conventional pharmaceutical compositions. Suchcompositions may be formulated so as to be suitable for oral orparenteral administration. The active ingredient may be combined inadmixture with a pharmaceutically acceptable carrier, which carrier maytake a wide variety of forms depending on the form of preparationdesired for administration, i.e., oral or parenteral. The compounds canbe used in compositions such as tablets. Here, the principal activeingredient is mixed with conventional tabletting ingredients such ascorn starch, lactose, sucrose, sorbitol, talc, stearic acid, magnesiumstearate, dicalcium phosphate, gums, or similar materials as non-toxicpharmaceutically acceptable diluents or carriers. The tablets or pillsof the novel compositions can be laminated or otherwise compounded toprovide a dosage form affording the advantage of prolonged or delayedaction or predetermined successive action of the enclosed medication.For example, the tablet or pill can comprise an inner dosage and anouter dosage component, the latter being in the form of an envelope overthe former. The two components can be separated by an enteric layerwhich serves to resist disintegration in the stomach and permits theinner component to pass intact into the duodenum or to be delayed inrelease. A variety of materials can be used for such enteric layers orcoatings, such materials including a number of polymeric acids ormixtures of polymeric acids with such materials as shellac, shellac andcetyl alcohol, cellulose acetate and the like. A particularlyadvantageous enteric coating comprises a styrene maleic acid copolymertogether with known materials contributing to the enteric properties ofthe coating. The tablet or pill may be colored through the use of anappropriate nontoxic dye, so as to provide a pleasing appearance.

The liquid forms in which the novel compositions of the presentinvention may be incorporated for administration include suitableflavored emulsions with edible oils, such as, cottonseed oil, sesameoil, coconut oil, peanut oil, and the like, as well as elixirs andsimilar pharmaceutical vehicles. Sterile suspensions or solutions can beprepared for parenteral use. Isotonic preparations containing suitablepreservatives are also desirable for injection use.

The term dosage form, as described herein, refers to physically discreteunits suitable as unitary dosage for warm-blooded animal subjects, eachunit containing a predetermined quantity of active component calculatedto produce the desired therapeutic effect in association with therequired pharmaceutical diluent, carrier or vehicle. The specificationfor the novel dosage forms of this invention are indicated bycharacteristics of the active component and the particular therapeuticeffect to be achieved or the limitations inherent in the art ofcompounding such an active component for therapeutic use in warm-bloodedanimals as disclosed in this specification. Examples of suitable oraldosage forms in accord with this invention are tablets, capsules, pills,powder packets, granules, wafers, cachets, teaspoonfuls, dropperfuls,ampules, vials, segregated multiples of any of the foregoing and otherforms as herein described.

The complement inhibiting activity of the compounds of this inventionhas been demonstrated by one or more of the following identified tests:(i) Test, Code 026 (C1 inhibitor) - This test measures the ability ofactivated human C1 to destroy fluid phase human C2 in the presence of C4and appropriate dilutions of the test compound. An active inhibitorprotects C2 from C1 and C4; (ii) Test, Code 035 (C3-C9 inhibitor) - Thistest determines the ability of the late components of human complement(C3-C9) to lyse EAC 142 in the presence of appropriate dilutions of thetest compound. An active inhibitor protects EAC 142 from lysis by humanC3-C9; (iii) Test, Code 036 (C-Shunt inhibitor) - In this test humanerythrocytes rendered fragile are lysed in autologous serum via theshunt pathway activated by cobra venom factor in the presence ofappropriate dilutions of the test compound. Inhibition of the shuntpathway results in failure of lysis; (iv) Forssman Vasculitis Test -Here, the well known complement dependent lesion, Forssman vasculitis,is produced in guinea pigs by intradermal injection of rabbitanti-Forssman antiserum. The lesion is measured in terms of diameter,edema and hemorrhage and the extent to which a combined index of theseis inhibited by prior intraperitoneal injection of the test compound at200 mg is then reported, unless otherwise stated; (v) Forssman ShockTest--Lethal shock is produced in guinea pigs by an i.v. injection ofanti-Forssman antiserum and the harmonic mean death time of treatedguinea pigs is compared with that of simultaneous controls; (vi)Complement Level Reduction Test - In this test, the above dosed guineapigs, or others, are bled for serum and the complement level isdetermined in undiluted serum by the capillary tube method of U.S. Pat.No. 3,876,376 and compared to undosed control guinea pigs; and (vii) Cap50 Test - Here, appropriate amounts of the test compound are added to apool of guinea pig serum in vitro, after which the undiluted serumcapillary tube assay referred to above is run. The concentration ofcompound inhibiting 50% is reported.

With reference to Table I, guinea pigs weighing about 300 g were dosedintravenously (i.v.) or intraperitoneally (i.p.) with 200 mg/kg of thetest compound dissolved in saline and adjusted to pH 7-8. One hour afterdosing, the guinea pigs were decapitated, blood was collected and theserum separated. The serum was tested for whole complement using thecapillary tube assay. Percent inhibition was calculated by comparisonwith simultaneous controls. The results appear in Table I together withresults of tests, code 026, 035, 036, Cap 50, % inhibition and Forssmanshock. Table I shows that the compounds of the invention possess highlysignificant in vitro and in vivo, complement inhibiting activity inwarm-blooded animals.

Some of the compounds of the present invention have been found topossess anti-coagulant activity as well as complement inhibitingactivity. The in vitro anti-coagulant activity (AC) of the compounds ofthis invention has been demonstrated by the following test: Citratedsheep plasma (CSP) is added to various dilutions of test compound in aMicrotiter® plate, the CSP sample mixtures are then recalcified with anisotonic sheep red blood cell (RBC) suspension. The sheep RBC's, kept insuspension throughout the slotting incubation time, become enmeshed inthe fibrin matrix if a clot forms. Upon centrifugation of the plate,untrapped RBC's form buttons, the sizes of which correspond to thedegree of clot inhibition; this providing a measure of anti-coagulantactivity (AC). Sodium heparin is used as a positive control and activityis reported in wells appearing in Table I.

                  TABLE I                                                         ______________________________________                                        Biological Activities                                                                                     Shunt                                                         Cl      C-Late  Inhibition                                                    026*    035*    036*   Cup   AC*                                  Compound    Wells   Wells   Wells  50*   Wells                                ______________________________________                                        (s-Triazine-2,4,6-tri-             >500   -2**                                yltrinitro)hexaace-                                                                         +3**  N       N            -2                                   tic acid    +3      N       N                                                 5,5-[(6-chloro-s-tri-                                                         azine-2,4-diyl)diimi-                                                                     +3      N       N            <-2                                  ino]diisophthalic                                                             acid tetrasodium salt                                                         5,5', 5"-(s-Triazine-                                                                     +3      N       N      >500  -2                                   2,4,6-triyltriimino)                                                                      +5      N       +1     triisophthalic acid                        hexasodium salt                                                               ______________________________________                                         N = Negative                                                                  * = Code designation for tests employed as referred herein.                   ** = Activity in wells a serial dilution assay. Higher well number            indicates higher activity. The serial dilutions are twofold.             

The computation of an Intrinsic Therapeutic Index (ITI) was devised tocorrelate the results expressed in wells obtained in the in vitro Code026 (C1 inhibitor) test and the in vitro anti-coagulant (AC) test into ameaningful value which would aid in the net evaluation of the activityof the compounds of this invention.

The ITI of a given compound may be defined as the antilogarithm of thelogarithmic (base 2) difference between the highest serial dilution inwells which is active in the Code 026 test and the highest serialdilution in wells providing activity in the anti-coagulant test. The ITIis thus a measure of the separation of anti-complement andanti-coagulant activities; the higher the numerical value the moretherapeutically useful the separation of activities.

The Intrinsic Therapeutic Index of the compounds of this invention arelisted in Table II.

                                      TABLE II                                    __________________________________________________________________________    Intrinsic Therapeutic Index                                                                  In Vitro Activity                                                             Complment Inhib-                                                                        Anti-Coagulant                                                                        Logarithmic                                                                             Intrinsic                                         iting Activity                                                                          Activity                                                                              Difference                                                                              Therapeutic                        Compound       (Wells) Code 026                                                                        (Wells) AC                                                                            Expressed As Wells                                                                      Index                              __________________________________________________________________________    (s-Triazine-2,4,6-triyltri-                                                                  +3        -2      +5        32                                 nitrilo)hexaacetic acid                                                                      +3        -2      +5        32                                 5,5'-[(6-Chloro-2-triazine-                                                   2,4-diyl)diimino]diisophthalic                                                               +3        -2      +5        32                                 acid tetrasodium salt                                                         5,5',5"-[s-Triazine-2,4,6-tri-                                                               +3        -2      +5        32                                 yltriimino)triisophthalic acid                                                               +5                +7        128                                hexasodium salt                                                               __________________________________________________________________________

EXAMPLE 1 (s-Triazine-2,4,6-triyltrinitrilo)hexaacetic acid

To a stirred solution of 11.71 g of iminodiacetic acid disodium saltmonohydrate and 5.5 g of sodium bicarbonate in 150 ml of water at roomtemperature is added a solution of 3.7 g of cyanuric chloride in 25 mlof acetone. The solution is stirred at room temperature for 2 hours thenis boiled to remove the acetone and is refluxed for 16 hours. Theresulting colorless solution is concentrated to 100 ml, filtered,acidified to pH 2 with 15 ml of concentrated hydrochloric acid andallowed to crystallize. The product is collected by filtration, washedwith a small amount of ice water followed by ethanol and ether. Thematerial is recrystallized from 50 ml of hot water, washed as above anddried by conventional means to yield 6.0 g of the product of the exampleas colorless crystals, mp 246°-249° C.

EXAMPLE 2 5,5'-[(6-Chloro-s-triazine-2,4-diyl)diimino]-diisophthalicacid tetrasodium salt

To a stirred solution of 18.1 g of 5 -aminoisophthalic acid in 200 ml ofwater plus 38.2 ml of 5 N sodium hydroxide is added 9.2 g of sodiumbicarbonate. The solution is cooled to 10° C. in an ice bath, then asolution of 9.2 g of cyanuric chloride in 50 ml of acetone is added. Themixture is stirred at room temperature for 10 minutes, then at 40°-45°C. for 31/2 hours. The solution is allowed to stand at room temperaturefor 16 hours and is filtered. The filtrate is concentrated to 150 ml anddiluted with 300 ml of absolute ethanol to give a colorless precipitate.The product is collected by filtration, washed with 75% aqueous ethanol,ethanol and ether and dried by conventional means to give 25.9 g ofcrude product. An 8.9 g portion of this material is dissolved in 50 mlof water, allowed to stand at room temperature for 2 hours, thenfiltered through diatomaceous earth. The filter is washed with 10 ml ofwater. The filtrate is diluted with 100 ml of absolute ethanol to give athick precipitate. The mixture is filtered and the product is washedwith (1:2) aqueous ethanol, ethanol and ether. The material is dried byconventional means to yield 7.64 g of a colorless powder as the productof the example.

EXAMPLE 3

5,5',5"-(s-Triazine-2,4,6-triyltriimino)triisophthalic acid hexasodiumsalt

To a stirred solution of 3.62 g of 5-aminoisophthalic acid and 1.85 g ofsodium bicarbonate in 80 ml of water plus 7.8 ml of 5 N sodium hydroxideis added 11.24 g of crude5,5'-[6-chloro-s-triazine-2,4-diyl)diimino]diisophthalic acidtetrasodium salt (prepared as described in Example 2). The reactionmixture is refluxed for 15 hours, then is filtered. The filtrate isdiluted with 100 ml of absolute ethanol to give a precipitate. Theprecipitate is collected by filtration and is washed with (8:10) aqueousethanol, 75% aqueous ethanol, ethanol and ether to give 14.2 g of crudeproduct. The product is warmed with 80 ml of water and 0.1 ml of 5 Nsodium hydroxide is added to achieve pH 9. The mixture is filteredthrough diatomaceous earth and the filtrate is diluted with 100 ml ofabsolute ethanol with formation of a thick paste on stirring. The pasteis filtered, stirred in absolute ethanol and filtered again, then iswashed with ether and dried by conventional means to give 9.9 g of acolorless powder as the product of the example.

EXAMPLE 4

    ______________________________________                                        Preparation of Compressed Tablet                                              Ingredient              mg/Tablet                                             ______________________________________                                        Active Compound         0.5-500                                               Dibasic Calcium Phosphate N.F.                                                                        qs                                                    Starch USP              40                                                    Modified Starch         10                                                    Magnesium Stearate USP  1-5                                                   ______________________________________                                    

EXAMPLE 5

    ______________________________________                                        Preparation of Compressed Tablet - Sustained Action                           Ingredient           mg/Tablet                                                ______________________________________                                        Active Compound      0.5-500 (as acid                                         as Aluminum Lake*, Micronized                                                                      equivalent)                                              Dibasic Calcium Phosphate N.F.                                                                     qs                                                       Alginic Acid         20                                                       Starch USP           35                                                       Magnesium Stearate USP                                                                             1-10                                                     ______________________________________                                         *Complement inhibitor plus aluminum sulfate yields aluminum complement        inhibitor. Complement inhibitor content in aluminum lake ranges from          5-30%.                                                                   

EXAMPLE 6

    ______________________________________                                        Preparation of Hard Shell Capsule                                             Ingredient            mg/Capsule                                              ______________________________________                                        Active Compound       0.5-500                                                 Lactose, Spray Dried  qs                                                      Magnesium Stearate    1-10                                                    ______________________________________                                    

EXAMPLE 7

    ______________________________________                                        Preparation of Oral Liquid (Syrup)                                            Ingredient             % W/V                                                  ______________________________________                                        Active Compound        0.05-5                                                 Liquid Sugar           75.0                                                   Methyl Paraben USP     0.18                                                   Propyl Paraben US      0.02                                                   Flavoring Agent        qs                                                     Purified Water qs ad   100.0                                                  ______________________________________                                    

EXAMPLE 8

    ______________________________________                                        Preparation of Oral Liquid (Elixir)                                           Ingredient             % W/V                                                  ______________________________________                                        Active Compound        0.05-5                                                 Alcohol USP            12.5                                                   Glycerin USP           45.0                                                   Syrup USP              20.0                                                   Flavoring Agent        qs                                                     Purified Water qs ad   100.0                                                  ______________________________________                                    

EXAMPLE 9

    ______________________________________                                        Preparation of Oral Suspension (Syrup)                                        Ingredient           % W/V                                                    ______________________________________                                        Active Compound      0.05-5                                                   as Aluminum Lake, Micronized                                                                       (acid equivalent)                                        Polysorbate 80 USP   0.1                                                      Magnesium Aluminum Silicate,                                                  Colloidal            0.3                                                      Flavoring Agent      qs                                                       Methyl Paraben USP   0.18                                                     Propyl Paraben USP   0.02                                                     Liquid Sugar         75.0                                                     Purified Water qs ad 100.0                                                    ______________________________________                                    

EXAMPLE 10

    ______________________________________                                        Preparation of Injectable Solution                                            Ingredient             % W/V                                                  ______________________________________                                        Active Compound        0.05-5                                                 Benzyl Alcohol N.F.     0.9                                                   Water for Injection    100.0                                                  ______________________________________                                    

EXAMPLE 11

    ______________________________________                                        Preparation of Injectable Oil                                                 Ingredient             % W/V                                                  ______________________________________                                        Active Compound        0.05-5                                                 Benzyl Alcohol          1.5                                                   Sesame Oil qs ad       100.0                                                  ______________________________________                                    

EXAMPLE 12

    ______________________________________                                        Preparation of Intra-Articular Product                                        Ingredient               Amount                                               ______________________________________                                        Active Compound          2-20 mg                                              NaCl (physiological saline)                                                                            0.9%                                                 Benzyl Alcohol           0.9%                                                 Sodium Carboxymethylcellulose                                                                          1-5%                                                 pH adjusted to 5.0-7.5                                                        Water for Injection qs ad                                                                              100%                                                 ______________________________________                                    

EXAMPLE 13

    ______________________________________                                        Preparation of Injectable Depo Suspension                                     Ingredient            % W/V                                                   ______________________________________                                        Active Compound       0.05-5                                                                        (acid equivalent)                                       Polysorbate 80 USP    0.2                                                     Polyethylene Glycol 4000 USP                                                                        3.0                                                     Sodium Chloride USP   0.8                                                     Benzyl Alcohol N.F.   0.9                                                     HCl to pH 6-8         qs                                                      Water for Injection qs ad                                                                           100.0                                                   ______________________________________                                    

We claim:
 1. A method of inhibiting the complement system in a bodyfluid which comprises subjecting said body fluid to the action of aneffective complement inhibiting amount of a compound of the formula:##STR6## wherein R₁ is selected from the group consisting of hydrogenand carboxymethyl; R₂ is selected from the group consisting ofcarboxymethyl and ##STR7## wherein R₄ is alkali metal; R₃ is selectedfrom the group consisting of chlorine and ##STR8## wherein R₁ and R₂ areas previously defined; and the pharmaceutically acceptable saltsthereof.
 2. A method according to claim 1, wherein R₁ is hydrogen; R₂ is##STR9## and R₃ is ##STR10##
 3. A method according to claim 1, whereinsaid body fluid is blood serum.
 4. A method according to claim 1,wherein said compound is (s-triazine-2,4,6-triyltrinitrilo)hexaaceticacid.
 5. A method according to claim 1, wherein said compound is5,5'-[(6-chloro-s-triazine-2,4-diyl(diimino]diisophthalic acidtetrasodium salt.
 6. A method according to claim 1, wherein saidcompound is 5,5',5"-(s-triazine-2,4,6-triyltriimino)triisophthalic acidhexasodium salt.
 7. A method of inhibiting the complement system in awarm-blooded animal which comprises internally administering to saidanimal an effective complement inhibiting amount of a compound of theformula: ##STR11## wherein R₁ is selected from the group consisting ofhydrogen and carboxymethyl; R₂ is selected from the group consisting ofcarboxymethyl and ##STR12## wherein R₄ is alkali metal; R₃ is selectedfrom the group consisting of chlorine and ##STR13## wherein R₁ and R₂are as previously defined; and the pharmaceutically acceptable saltsthereof.
 8. A method according to claim 7, wherein R₁ is hydrogen; R₂ is##STR14## and R₃ is ##STR15##
 9. A method according to claim 7, whereinsaid compound is administered intra-articularly.
 10. A method accordingto claim 7, wherein said compound is(s-triazine-2,4,6-triyltrinitrilo)hexaacetic acid.
 11. A methodaccording to claim 7, wherein said compound is5,5'-[(6-chloro-s-triazine-2,4-diyl)diimino]diisophthalic acidtetrasodium salt.
 12. A method according to claim 7, wherein saidcompound is 5,5',5"-(s-triazine-2,4,6-triyltriimino)triisophthalic acidhexasodium salt.